Regulations in place in many municipalities require that the so-called "P-trap" assembly (i.e., the waste-water piping under sinks and the like) be insulated so as to prevent injury from contact with hot metal surfaces. Wheelchair bound individuals are at particular risk.
The required thermal insulation may be supplied by wrapping or otherwise applying lengths of insulation (such as of foam rubber and the like) about the pipes. Such practices are however undesirable for a number of reasons: application is often difficult and time-consuming; the applied insulating material tends to become disoriented and displaced; the finished installation is typically unaesthetic; and often the result is simply ineffective.
The prior art suggest a wide variety of pipe covering techniques and structures. For example, Far et al U.S. Pat. No. 3,598,157 discloses preformed covering pieces made of foamed plastics and configured for various pipe fittings. Blundell U.S. Pat. No. 4,205,105 shows an elongated pipe-insulating structure that is axially slit along one side, and Martin U.S. Pat. No. 3,402,731 provides foamed insulating sleeves for pipe elements.
U.S. Pat. Nos. 2,650,180, 2,937,662, 3,153,546, 3,559,694, 4,441,743 and 4,840,201, to Walker, Green, Dunn, Volberg, Steenbergen and Botsolas, respectively, all show encased insulating structures applied to pipes and fittings; U.S. Pat. Nos. 3,960,181, 4,463,780 and 4,669,509, to Baur et al, Schultz et al and Botsolas, respectively, provide one-piece covering wrappings fabricated from flexible plastic materials; and U.S. Pat. Nos. 3,177,528 and 3,719,209, to Flower et al and Rush et al, respectively, are directed to electrically insulated coatings for pipe fittings and to extruded plastic plumbing traps.
Despite the activity in the art indicated by the foregoing, there has been a need for means by which under-sink piping can quickly, easily, and inexpensively be thermally insulated. Although Applicants' U.S. Pat. Nos. 5,054,513 and 5,163,469, and their copending application Ser. No. 07/944,836, provide thermal insulation systems and installations by and in which the foregoing needs are well satisfied, it would of course be desirable to provide improvements in the fit, insulation effects, and convenience of use of such articles of insulation.